BACKGROUND OF THE INVENTION
[0001] The present invention relates to a multi-stage assembling robot having a progressive
feeding device.
[0002] Heretofore, there has been used a robot provided with a rotary feeder and a progressive
feeding device connected to a power press. However, the robot is complicated in construction
and expensive.
SUMMARY OF THE INVENTION
[0003] An object of the present invention is to provide robot for a progressive multi-stage
press machine using a die set and having a progressive pick-and-place device, whereby
the robot may be simplified in construction, reduced in size, and manufactured at
a low cost.
[0004] According to the present invention, there is provided a multi-stage assembling robot
comprising, a die set having a base plate, vertical guide posts securely mounted on
the base plate, a horizontal cylinder plate securely mounted on top portions of the
guide posts, an upper movable plate and a lower movable plate which are slidably mounted
on the guide posts, at least three sets of upper and lower dies mounted on the upper
movable plate and base plate, a first cylinder mounted on the cylinder plate, the
cylinder having a piston rod which is connected to the upper movable plate, a second
cylinder mounted on an underside of the base plate, the second cylinder having a piston
rod which is connected to the lower movable plate, a work pick-and-place device mounted
on the lower movable plate provided to be reciprocated in the horizontal direction
and reciprocated in the vertical direction so as to feed works to lower dies, at least
three parts pick-and-place devices radially mounted on the base plate, each of the
part pick-and-place devices being provided to be reciprocated in the horizontal direction
and reciprocated in the vertical direction so as to feed parts one by one to a corresponding
lower die.
[0005] The work pick-and-place device has at least three sets of grasping opposite fingers,
each set of grasping fingers are reciprocated by opposite cylinders, and each of the
part pick-and-place device has a chuck for grasping a part.
[0006] These and other objects and features of the present invention will become more apparent
from the following detailed description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0007]
Fig. 1a is a side view of a robot according to the present invention;
Fig. 1b shows a part of Fig. 1a;
Fig. 2 is a front view showing a part of the robot;
Fig. 3 is a plan view of the robot;
Fig. 4 is a side view showing a part pick-and-place device;
Figs. 5a to 5f show a finished produce and parts for the product;
Fig. 6 is a plan view of a work pick-and place device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0008] Referring to Figs. 1a, 1b and 2, two vertical guide posts 1 are securely mounted
on a base plate 2. An upper movable plate 8 and a lower movable plate 10 are slidably
mounted on the guide posts 1 by slidably engaging guide bushes 3 and 4, interposing
ball sliders 5 between the guide bush and guide post 1.
[0009] A horizontal cylinder plate 7 is secured to the guide post 1 at the top of each post
and secured thereto by screw. A hydraulic cylinder 6 such as an oil hydraulic cylinder
or pneumatic cylinder is vertically mounted on the cylinder plate 7 and secured thereto
by screws. At least one pneumatic cylinder 11 is secured to the underside of the base
plate 2, and a piston rod 12 thereof connected to the lower movable plate 10.
[0010] The piston rod 9 is secured to the movable plate 8. The movable plate 8 has a punch
53, and dies 55 and 57 (Fig. 2). On the base plate 2, a lower die 54, 56 are mounted.
[0011] Mounted on the base plate 2 is a first pick-and-place device 13 for feeding works
A to D and for taking out a processed work (Fig. 2).
[0012] Referring to Figs. 1a, 3 and 6 showing the work pick-and-place device 13, a pair
of slide guide rails 16 are securely mounted on the lower movable plate 10 parallel
with each other at the opposite sides of the lower die 54. A pair of slide blocks
15 are slidably mounted on each of the guide rails 16. A pair of L-shaped supporting
plates 20 and 21 are secured to respective slide blocks 15. The ends of the supporting
plates 20, 21 are connected by a connecting plate 22. A supporting plate 23 is secured
to the ends of the slide guide rails 16. A pneumatic cylinder 24 is mounted on the
supporting plate 23 and a piston rod 25 is connected to the connecting plate 22.
[0013] Three pairs of grasping actuators are provided on the supporting plates 20, 21. Each
grasping actuator comprises opposite pneumatic cylinders 18 and 19 secured to the
opposite supporting plates 20, 21. The cylinders 18 and 19 are positioned on a first
position P1, second position P2, and a third position P3 at predetermined equidistances,
respectively. Opposite grasping fingers 28, 29 are secured to piston rods 26, 27 (Fig.
1b) of cylinders 18 and 19 by nuts 22 for grasping a work.
[0014] Thus, the cylinders 18 and 19 on the supporting plates 20, 21 are reciprocated on
the slide guide rails 16 between the positions P1, P2, P3 and P4 by the operation
of the cylinder 24.
[0015] As shown in Fig. 3, three part pick-and-place devices 14a, 14b, and 14c are radially
provided. Each device has the same construction as the other devices. Therefore, respective
parts of devices are identified by the same reference numerals. Figs. 4 shows the
part pick-and-place device 14a. The device has an elevating device 30, The device
30 has a pair of guide posts 32 secured on a base plate 31 which is securely mounted
on the base plate 2. A movable plate 34 is vertically slidably mounted on the guide
posts 32, interposing guide bushes 33 respectively. The movable plate 34 is connected
to a piston rod 36 of a pneumatic cylinder 35 which is secured to the base plate 31.
A slide guide rail 37 is secured to the movable plate 34. A slide block 38 is slidably
mounted on the slide guide rail 37. A supporting plate 40 is secured to the slide
block 38. A horizontal pneumatic cylinder 42 is secured to the supporting plate 40
through a connecting plate 41, and a piston rod 43 of the cylinder 42 is connected
to the slide guide rail 37 through a connecting plate 44. On the underside of the
supporting plate 40, a horizontal pneumatic cylinder 39 having a chuck 39a is secured
by screws 39b.
[0016] The chuck 39a is opened in a normal state. The chuck is closed for gripping a part
B and opened again for releasing the work in accordance with the operation of the
cylinder 39. The chuck device is well known.
[0017] As shown in Fig. 3, a guide rail 46 is connected to a well known parts feeder 45
and communicated with a groove 47 provided on the base plate 31.
[0018] The part pick-and-place device 14b is provided for feeding a part C, and the device
14c is provided for feeding a part D.
[0019] Referring to Figs. 2 and 3, on a progressive feed line, a guide rail 49 is securely
mounted. Slidably mounted on the guide rail 49 is a slide block 50 on which a part
holder 48 is mounted. The slide block 50 is connected to a piston rod 52 of a pneumatic
cylinder 51 mounted on the guide rail 49.
[0020] The illustrated embodiment of the present invention is provided for assembling parts
into a thermo-actuator provided in a wax-pellet thermostat for a cooling system of
an automotive engine.
[0021] Fig. 5a shows the thermo-actuator, and Figs. 5b to 5f shows respective parts for
the thermo-actuator.
[0022] In operation, a part A for a first step which has been worked and assembled at a
previous stage is introduced in the part holder 48 through a chute (not shown) as
shown in Figs. 2 and 3. The part A is transferred to the position P1 together with
the part holder 48 by the piston 52 of the pneumatic cylinder 51.
[0023] On the other hand, in the part pick-and-place device 14a (Fig. 4), the chuck 39a
which has been opened is lowered, holds a part B for the first step, and raised by
the piston 36 of the pneumatic cylinder 35. The piston 43 of the pneumatic cylinder
42 causes the supporting plate 40 and chuck 39a to move forwardly to the position
P1. Then, chuck 39a is lowered by the piston 36 so that the part B is inserted into
the part A. The chuck 39a is opened and raised and returned to the original position,
keeping the chuck opened. Thereafter, the upper movable plate 8 is lowered by the
operation of the cylinder 6, so that the punch 53 is inserted in the part B to form
it into a proper shape to fit in the part A, thereby forming a fist step work assembly
A1. Then, the movable plate 8 is raised.
[0024] Next, the piston rods 26 (Fig. 1b) of the cylinders 18 and 19 are forwardly moved,
so that the fingers 28 and 29 at the position P1 grasp the work assembly A1. Then,
the base plate 10 of the work pick-and-place device 13 is raised by the operation
of the pneumatic cylinder 11, and moved to the position P2 in Figs. 2 and 3, and lowered,
so that the work assembly A1 is inserted in the die 54. Then, the fingers 28 and 29
are opened, raised, returned to the position P1, and lowered.
[0025] In the next step, next parts A and B for a second step are engaged with each other
in the above described operation to form a second step work assembly A1. On the other
hand, a part C for the first step which has been assembled by another device (not
shown) is inserted in the first step work assembly A1 by the part pick-and-place device
14b. And then, the upper movable plate 8 is lowered and raised, so that the part B
is fixed in the part A for the second step. At the same time, the part C is engaged
in the part B of the first step at the position P2 by the dies 54 and 55, thereby
forming a first step work assembly A2.
[0026] Here, although the work assembly A1 has a space
a (Fig. 2) sufficient for receiving the fingers 28 and 29, the work assembly A2 engaged
in the die 54 has not such a sufficient space. Hence, the work assembly A2 is raised
by a collar 60 secured to a piston rod 59 of a pneumatic cylinder 58 so as to form
a space
a.
[0027] Thus, fingers 28, 29 at the positions P1 and P2 carry the second step work assembly
A1 and the first step work assembly A2 to the positions P2 and P3. At the position
P3, the first step work assembly A2 is inserted in a die 56.
[0028] In the next step, a third step work assembly A1 and a second step work assembly A2
are assembled in the same operation as the above described operation. On the first
step work assembly A2 at the position P3, the part D is engaged by a die 57, so that
a first step assembly A3 which is a finished work is assembled.
[0029] Next, fingers 28, 29 at the positions P1, P2 and P3 carry the assemblies A1, A2 and
A3 to the position P2, P3 and P4. At the position P4, the finished work assembly A3
(Fig. 5a) is discharged by a chute (not shown).
[0030] Thereafter, three assemblies A1, A2 and A3 are assembled at the same time at every
cycle of the operation.
[0031] In the robot, automatic centering means is provided as described below.
[0032] The inner diameter of each of the cylinders 18 is set to a larger value than that
of the cylinder 19 at the other side, so that each cylinder 18 has a larger air pressure
than that of the cylinder 19. Therefore, the part engaged with the finger 28 of the
cylinder 18 is not moved if the work is pushed by the finger 29 of the cylinder 19.
Namely, the position of the work is determined by only the finger 28 of the cylinder
18. Thus, the centering of the work is accurately determined with respect to the center
of each die. Consequently, the break of the die due to eccentric positioning of the
work is prevented.
[0033] In accordance with the present invention, only one robot can assemble four parts
into a finished product. Thus, the robot can be manufactured in small size and at
a low cost.
[0034] While the invention has been described in conjunction with preferred specific embodiment
thereof, it will be understood that this description is intended to illustrate and
not limit the scope of the invention, which is defined by the following claims.